Apparatus for determining the zone of lost circulation of drilling mud



APPARATUS FOI R DETERMINING THE ZONE OF April 1952 P E CHANEY ET AL 2,592,378

LOST CIRCULATION OF DRILLING MUD Filed Oct. 50, 1948 2 SHEETSSHEET l 3o INVENTOR. PRESTON E. OHANEY BY WILLIAM E. BARNES ATTORNEYS April 1952 P. E. CHANEY ET AL APPARATUS FOR DETERMINING THE ZONE OF LOST CIRCULATION OF DRILLING MUD Filed 001;. so, 1948 2 SHEETS-SHEET 2 Y M R A H MC V. mE N 0 T S E P y WILLIAM E. BARNES ATTORNEYS UNITED STATES Patented Apr. 8, 1952 APPARATUS FOR DETERMINENG THE ZONE OF LOST CIRG ULATION F DRILLING MUD TENT OFFICE Application. Octcbcr 30, 1948, Serial No. 57,458

3 Claims. 1

This invention relates to devices for the location of the level at which liquid leaks out of well boreholes into the surrounding strata, and is especially adapted to the art of drilling oil wells for the determination of zones of lost circulation of drilling mud.

The drilling of deep wells through strata of varying composition in the earth requires that a liquid be circulated to the drilling bit to serve as a coolant, a lubricant and, in the process of recirculating, a means of washing the cuttings to the ,earths surface. This method of assisting the penetration of the drill bit is particularly useful in drilling oil wells where the circulating fluid takes the form of a drilling mud.

In the specific instance of drilling oil wells, a prepared drilling fluid or mud containing finely divided mineral matter and water is normally used, the purpose being to increase the viscosity and the specific gravity of the drilling fluid, to

increase the hydrostatic head and otherwise improve drilling conditions. As wells increase in depth and formation pressures increase, it becomes necessary to increase the specific gravity of the drilling fluid in order to prevent the flow of fluids from the formations penetrated into the borehole. Such increase is customarily effected by adding-to the drilling fluid a weighting material, forexample, barytes. The higher specific gravity of the drilling fluid will cause the breakdown of earth strata and permit the escape of the drilling fluid from the well borehole. This is immediately noticeable on the earths surface by a marked decrease in the rate at which the drilling fluid returns from the borehole.

It then becomes desirable to discover the location of the point of leakage in the well bore and seal that area against further drilling fluid loss in order to continue the drilling operation. Once the leak is located it is a comparatively simple matter to seal it, usually with cement, and redrill through the seal.

It is a primary object of this invention to provide an apparatus which will accurately locate the zone of leakage in a Well borehole through which the drilling mud escapes.

A further object is to provide a leak detecting device which will accurately locate the zone of leakage within the well borehole while submerged in the liquids which normally fill boreholes in drilling operations.

Another object is to provide apparatus which is "purely mechanical in its operation and does not require electrical cables for the transmission of borehole information nor the use of electrical equipment in the device which could be damaged by conditions existing in deep boreholes. I

Yet another object is to provide apparatus the operation of which can be controlled from the ground surface and which can be suspended in the well borehole by standard equipment used for drilling operations.

Other objects and advantages of this invention will be apparent in the course of the detailed descriptions which follow, taken with the accompanying drawings in which:

Figure 1 illustrates a well borehole in which the device is suspended,

Fi ure 2 is an elevation in section showing the relative position of the component parts of the device when positioned above a zone of leakage,

Figure 3 is an elevation in section showing the device in operation below a leak,

Figure 4 is an enlarged section on line i-A of Figure 2.

Figure 1 shows a section of an uncased borehole in which the drilled portion is indicated by the numeral Iii. Drill pipe ll suspends the leak detecting device l2 by means of a drilling liquid inlet tube 53 attached to pipe H by coupling 14.

A leak i5 is shown in side wall ill through which the drilling fluid escapes into strata 15. To clarify the operation of this device, which will be explained in detail later in this specification, the level of the subsurface Water and drilling fluids is shown as having risen within the well borehole above leak to any point such as surface H which is indicative of the condition existing after drilling operations cease and the leak detecting device of this disclosure is lowered into the hole. Arrows at leak 15 indicate the flow of the liquids from the borehole outward to strata l6.

With the general application of the device shown, Figures 2 and 3, in which like parts are similarly designated, illustrate the internal action of the device as it approaches and passes the leakage zone. Drilling liquid inlet tube [3 longitudinally traverses housing through the entire length. In the lower part of the housing 20, the liquid inlet is constricted, or otherwise obstructed below apertures 22, as at 21 which assists in the operation of the device as will be explained later in detail. Apertures 22 are pierced in inlet tube [3 to permit the drilling liquid to enter housing 20 during its operation. A rotor assembly 23 slidably engages inlet tube l3 within housing 29 and is Vertically positioned by stops 2d and 25 on inlet tube l3. The rotor assembly 23 comprises a body 26 in which plungers 21 are radially recessed and are urged inwardly by springs 35 but are free to move outwardly when the centrifugal force exceeds the force of the springs. An impeller wheel 28 with conventional turbine blades is mounted on the body of the rotor assembly 23 and is rigidly fixed thereto. A seal 29, slidably engaging the inner wall of body and inlet tube 13, forms a part of rotor assembly 23 which causes it to slide up and down on inlet tube [3 under the eiTect of liquid pressure. Exterior of housing 20, flexible contact seal extends from the outside housing 20 to the inner wall of the borehole, designated as [0 (Fig. 1), forming a barrier to pressures from below.

Referring to Figure 4, a sectional view through the housing and the rotor in the non-operating position is shown. Centered within the well borehole I0 by sealing gasket 30 the leak detecting device l2 as outlined by housing 20 is indicated as it is suspended in the borehole. Inlet tube l3, by which housing 28 is suspended from the drill pipe, is centered within the device. The turbine blades of the impeller wheel 28 are concentrically disposed about inlet tube 13 with the spring retaining plungers 21 shown within the body of the rotor housing 23 in dotted line. Striking lugs 34 are illustrated as above the seal 29 which supports the rotor assembly 23 within housing 26.

In considering the operation of the device it will be necessary to refer to all the figures in the drawing and to complete the numbering of those figures insofar as it is required to refer to parts of the apparatus which have not yet been discussed. In Figure 1 we have seen that the device [2 is lowered into an uncased well borehole designated as l8. By means of the liquid inlet tube I3 the device l2 has been attached to drill pipe II from which it receives drilling mud or other liquid under pressure. If we consider the leak detecting device to be suspended in the well borehole above the leaking stratum, the drilling mud or other liquid will pass freely through inlet tube [3 and out the bottom to continue down the drill hole and out through the zone of lost circulation. There will be no change in the position of the rotor assembly 23 in housing 20, which condition is shown by the position of the component parts and the flow arrows in Figure 2.

It remains to consider the operation of the device when it is suspended below the leak the location of which is sought. The circulation of the drilling mud into and out of the drill hole being interrupted due to the leak in the well borehole, the drilled out portion is filled with drilling liquid and subterranean water, which may rise above the leakage zone as described in relation to Figure 1 after the circulation ceases. The drilling mud or substitute liquid being forced downward through drill pipe H and inlet tube l3 passes out through the constricted lower end of the inlet tube and into a static body of liquid, turns upward toward the leakage zone to escape, following the flow of the liquids standing in the borehole. The velocity head of the liquid and the pressure with which it is forced into the drill pipe causes the liquid to enter apertures 33 (Figure 1) into the housing 20 and upward against slidable seal 29 (Figure 3) causing the rotor assembly 23 to lift and press against stop 25 on inlet tube 53 and there to rotate setting up vibrations as fully described in discussing Figure 3.

To clarify the operation of the device and 4 further explain the construction features, the operation of Figure 3, which shows the elements in the vibrating position, will be discussed in detail. Drilling liquid, as shown by arrows. descends through inlet tube [3 and passes through the constriction in the lower section of this tube and transmits its velocity head to the liquid in the drill hole. It will be understood that the leak detecting device is in position below leak l5 and submerged in the borehole liquids, as shown in Figure 1. Returning to Figure 3, the liquid being forced downward through inlet tube i3 is turned upward by the body of static liquid in the borehole and exerts its velocity head against the lower side of housing 20, seal 30 and upward through apertures 33 in the housing 20. The pressure transmitted to the interior of housing 20 urges rotor assembly 23 upward by pressure on sliding seal 29 until it is halted by stops 25 which places the impeller wheel 28 in operating position with apertures 22 in inlet tube IS. A part of the velocity head of the liquid descending the drill pipe is retained by the constriction in the lower section of inlet tube I3 and is exerted against impeller wheel 28 as a jet through apertures 22 causing rotor assembly 23 to rotate. Plungers 21 are urged outwardly by centrifugal force against retaining springs 35 into striking relation with studs 34 as the impeller wheel 28 is rotated, thereby causing repeated vibrations to be set up in the housing 28 by the continuous striking of the plungers 2'! on the studs 34. The vibrations thus generated are transmitted by the housing through inlet tube !3 to the drill pipe H and thence to the ground level for detection by means of any of the well known transducing devices either electrical or mechanical. The velocity head of the liquid being forced downwardly through inlet tube I3 is maintained by the continued flow through the lower part of the housing l2 in support of the slidable rotor seal 29 and out through the apertures 32. portion of the liquid driving the impeller wheel passes out of the housing through apertures 3| in a continuous flow and joins the course of the circulating liquid upward in the borehole.

From the details of the various parts of the device and the discussion of the operation, it will now be evident that the leak in the well borehole can be bracketed by raising and lowering the mechanism from positions of operation to inoperative points above them and, thus, determine the exact location of the point of outflow of the drilling liquid. As is evident, the quantity of liquid within the well borehole will have no effect upon the operation of the device as the position of the leak is the only determining factor. Further, the device operating purely on mechanical principles and not being dependent upon sources of electrical energy carried through fragile conductors, satisfactory results will be obtained under all practical working conditions.

Having now described and illustrated one form of the invention, it will be understood that the invention is not to be limited to the specific form or arrangement of parts described and shown herein except insofar as such limitations are specified in the appended claims.

We claim:

1. In combination with a well drill pipe a device for locating zones of lost circulation of drilling mud in well boreholes comprising a housing having in the upper, intermediate and lower portions thereof apertures arranged to allow flow The' of liquid between the upper, intermediate and lower portions of the housing and the borehole; an inlet tube, having apertures therein adjacent the upper apertures in the housing, constricted at the lower end and adapted to be detachably attached to said drill pipe at the upper end thereof, centrally disposed in said housing; a rotor assembly concentrically disposed within said housing in sliding engagement with said inlet tube; said rotor assembly including a body member, spring-retained plungers circumferentially spaced within said body member adapted to move outwardly therefrom during rotation of said member, a rotatable varied impeller wheel mounted on the body member, and a flexible gasket seal connected to the bottom of said body member and in sealing engagement with the interior of said housing; upper and lower stops on said inlet tube, said upper stop positioned below said apertures in said tube, limiting the vertical slidable movement of the rotor assembly means above the intermediate apertures in said housing, said lower stop spaced above the bottom of the housing limiting the downward movement to below said intermediate apertures;

I striking lugs peripherally arranged in said housing to receive blows from the spring retained plungers in the body member during the rotation of said rotatable means, thereby setting up vibrations in said drill pipe; and a second flexbile seal gasket exterior of said housing in sealing engagement with the drill hole wall to direct the operating liquid pressure through the lower apertures into said housing to position the rotatable means in operating relation with the apertures in said inlet tube.

2. A device for the sonic detection of zones of lost circulation of drilling mud in well boreholes comprising a tubular suspending member adapted to transmit liquid under pressure; a housing divided into upper, intermediate and lower portions positioned on the lower end of said suspending member having apertures peripherally spaced in the wall of each portion thereof arranged to allow flow of liquid between the upper, intermediate and lower portions of the housing and the borehole; an inlet tube extending concentrically through said housing having a plurality of apertures spaced circumferentially therein constructed to divert a part of the liquid into the upper portion of the housing and to pass the remainder of said liquid downwardly through said housing; a liquid operable rotor in said housing slidably engaging said inlet tube, means normally supporting said rotor above said apertures in the lower portion of said housing, said rotor adapted to be moved upwardly into operating position adjacent the apertures in said inlet tube; vibration creating means connected with and actuated by rotation of said rotor; and a seal, exterior of said housing, adapted to engage the periphery of said well borehole and confine the liquid pressure externally of the lower apertures in said housing whereby the liquid pressure positions said rotor adjacent said apertures in the inlet tube in position to rotate.

3. A device for the sonic detection of zones of lost circulation of drilling mud; in well boreholes comprising a hollow suspending member adapted to transmit liquid under pressure; a housing divided into upper, intermediate and lower portions with peripherally spaced apertures in each portion to permit the flow of liquid therethrough, said housing being positioned on the lower end of said suspending member; a tubular passage within said housing in prolongation of said suspending member, having apertures therein to communicate with the upper portion of said housing, and constructed to proportionally direct the liquid under pressure partly through said apertures and the remainder downwardly through said housing; vibrating means in slidable engagement with said tubular passage adapted to be lifted into operating position adjacent said apertures in said tubular passage by the pressure of liquid in the lower portion of said housing; and liquid pressure confining means exterior of said'hou'sing, positioned between the lower and intermediate apertures thereof to direct the liquid pressure into the lower section of said housing.

PRESTON'E. CHANEY. WILLIAM E. BARNES.

REFERENCES CITED The following reierences are of record in the file of this patent:

UNITED STATESPATEN'I'S Number Name Date 1,440,778 Foster Jan. 2, 1923 1,652,472 Erwin et al Dec. 13, 1927 2,379,138 Fitting, Jr. et al. June 26, 1945 

3. A DEVICE FOR THE SONIC DETECTION OF ZONES OF LOST CIRCULATION OF DRILLING MUD IN WELL BOREHOLES COMPRISING A HOLLOW SUSPENDING MEMBER ADAPTED TO TRANSMIT LIQUID UNDER PRESSURE; A HOUSING DIVIDED INTO UPPER, INTERMEDIATE AND LOWER PORTIONS WITH PERIPHERALLY SPACED APERTURES IN EACH PORTION TO PERMIT THE FLOW OF LIQUID THERETHROUGH, SAID HOUSING BEING POSITIONED ON THE LOWER END OF SAID SUSPENDING MEMBER; A TUBULAR PASSAGE WITHIN SAID HOUSING IN PROLONGATION OF SAID SUSPENDING MEMBER, HAVING APERTURES THEREIN TO COMMUNICATE WITH THE UPPER PORTION OF SAID HOUSING, AND CONSTRUCTED TO PROPORTIONALLY DIRECT THE LIQUID UNDER PRESSURE 